Developing, developed countries can reduce emissions from construction

Developing, developed countries can reduce emissions from construction


Switching from unsustainable building practices to using alternative low-carbon building materials can help developing and developed countries reduce emissions from construction.

The above-featured image is for illustration and is of GreenBiz


UN report outlines how developing, developed countries can reduce emissions from constructions

If India uses recycled materials, it could reduce emissions in the material cycle of residential buildings by 50-70 per cent.

 Processing of cement, the binding agent in concrete, contributes 7 per cent of global carbon emissions, according to a new UNEP report. Photo: iStock

Developing countries should switch from unsustainable building practices to using alternative low-carbon building materials to reduce greenhouse gas emissions, a new UN report highlighted.

The world adds buildings equivalent to the size of Paris every five days, states the report — Building Materials and The Climate: Constructing A New Future — by the United Nations Environment Programme (UNEP), and the Yale Center for Ecosystems and Architecture.

About 37 per cent of global greenhouse gas emissions can be traced back to the built environment sector, which includes buildings, the distribution systems that supply water and electricity, and the roads, bridges, and transportation systems.

The UNEP report makes a case for “Avoid-Shift-Improve” strategies to reduce emissions. “Avoiding” emissions through circularity to ensure waste is eliminated while extending a building’s life, “Shifting” to sustainable materials, and “Improving” the production of conventional materials such as concrete, steel, aluminium, plastics, glass and bricks.

Greenhouse gas emissions from the built environment are categorised into two groups: embodied emissions and operational emissions.

Embodied emissions are all the emissions associated with the construction and demolishing of a building. They also include emissions from extraction, manufacturing, transport and on-site construction of building materials and “end-of-life” demolition or reuse.

Operational emissions are the emissions generated while maintaining the building’s indoor “comfort levels,” including by heating, cooling, lighting and electrical appliances.

Indirect operational emissions from residential buildings make up a majority of emissions (11 per cent), while embodied emissions from the use of concrete, steel and aluminium account for at least six per cent.

So far, the focus has been on operational emissions. The UNEP, however, warns that embodied carbon (the amount of carbon dioxide across the life cycle of the built environment process) is projected to surge from 25 per cent to nearly half (49 per cent) by 2050, whereas the share of operational carbon emissions will shrink due to increased adoption of renewable energy and improvement of energy-efficient buildings.

Developed countries, it adds, should focus on renovating existing and ageing building stock. Renovating a building generates 50-75 per cent fewer emissions than new construction, the report highlighted.

For new buildings, the experts call for incorporating circular design strategies such as the design for disassembly. It is a design process that enables the recovery of products, parts and materials when a building is disassembled or renovated. This can reduce greenhouse emissions by 10-50 per cent.

“Despite growing awareness, most contemporary material cycles continue to be more linear than circular. As a result, non-renewable, energy-intensive materials still supply the majority of demand,” the report reads.

The report added that a new supply-and-demand model should be developed. Tasks such as carefully dismantling buildings for storing, preparation and maintenance of second-cycle materials for resale will enable circular economies while providing job opportunities.

If G7 countries and China use recycled materials, they could reduce emissions in the material cycle of residential buildings by 80 to 100 per cent by 2050. In India, the reductions could reach 50-70 per cent, the report quotes the International Resource Panel (a scientific panel of experts that aims to help nations use natural resources sustainably).


Source: UNEP

They also state that increasing the lifetime of buildings creates significant opportunities to reduce aggregate embodied carbon.

The second principle is to switch towards properly managed bio-based materials. “To reach net zero emissions in the built environment sector, the building materials of the future will need to be procured from renewable or reusable sustainable sources wherever possible,” the report reads.

Of the available options, mass timber has emerged as an attractive alternative to carbon-intensive concrete and steel due to its potential for scalability, sustainability, strength and flexibility in mid-rise urban buildings.

Bamboo can be processed and manufactured into a variety of composite materials called engineered bamboo. This version has demonstrated structural performance similar to that of cross-laminated timber and steel.

As for the third principle “improve”, UNEP recommended electrifying and decarbonising the energy that is supplied to the production and maintenance of materials, buildings and urban infrastructure across their life cycle.

Processing of cement, the binding agent in concrete, contributes 7 per cent of global carbon emissions. Solutions such as reducing the clinker (produced from limestone and chalk)-to-cement ratio and increasing the share of cement alternatives, among others, could help in decarbonising the sector.

Another technology that could potentially be used is Carbon capture and utilisation for concrete production (CCU concrete). It is a process of removing carbon from the atmosphere and storing it within the building material itself over time

It is estimated that CCU concrete can remove 0.1 to 1.4 gigatonnes of CO2 by 2050. “However, there are conflicting opinions as to whether the benefits of increased strength and optimisation of materials will outweigh the carbon costs of capturing, transporting and incorporating the captured CO2 into concrete products,” reads the report.

Avoiding raw material extraction by promoting steel reuse and producing steel from scrap (discarded steel or steel product) can save around 60-80 per cent of energy, the report noted.

It also helps to reduce steel demand by extending building lifetimes, and switching to circular bio-based materials such as engineered timber and bamboo, it added.

Using renewable energy for aluminium production is important and producing aluminium from scrap can reduce the energy demand by 70-90 per cent.




Circular Built Environment Playbook to advance regenerative


A Circular Built Environment Playbook is most welcome during and at a time of a worldwide overbuilt environment and an omnipresent culture of infinite resources.  It shall be doubly rewarding if this Playbook leads to advance regenerative.  Let us wait and see.



WorldGBC launches Circularity Accelerator – a groundbreaking global programme to advance circular and regenerative built environments



World Green Building Council (WorldGBC) and its network of over 70 Green Building Councils are #BuildingtoCOP27 by launching Circularity Accelerator — a global programme to accelerate the adoption of circular economy and resource efficiency principles in the building and construction sector.

Last week, the United Nations (UN) reported we have a 50% chance of exceeding 1.5°C of global heating in the next five years. Between the UN Climate Summit of COP21 in Paris and COP26 in Glasgow, the global economy consumed 70% more raw materials than the Earth can safely replenish. [1]

Our planet thrives through circular, natural and regenerative systems, which are being damaged by the impacts of the built environment:

  • The built environment is responsible for 37% of global energy-related carbon emissions, and the construction sector accounts for around 40% of global resource demand every year. By 2050, two thirds of the global population will live in cities, consuming 75% of the world’s natural resources, producing 50% of global waste and over 60% of greenhouse gas (GHG) emissions. [2]
  • Over one-third of the materials used worldwide are for buildings, but less than 9% of global materials consumed are circular, i.e. kept in productive cycles of use. [1]
  • The impact of this resource use-associated GHG emissions and pollution and plunging biodiversity accelerates climate change and the decline of life-sustaining ecosystem services such as the maintenance of clean water and productive soils.

Cristina Gamboa, CEO, WorldGBC, said: 

“The UN has reported we have a 50% chance of exceeding 1.5°C of global heating in the next five years. Over one-third of the materials used globally are for buildings, but less than 9% of global materials consumed are kept in productive cycles of use.

“The impact of this resource use — associated GHG emissions and pollution and plunging biodiversity — accelerates climate change and the decline of life-sustaining ecosystem services such as the maintenance of clean water and productive soils. These impacts unequally affect the most vulnerable communities and economies around the world. But that can and must change.

“To scale the implementation of resource efficiency solutions as we approach COP27, our new Circularity Accelerator programme is already bringing together experts and leaders from across our Green Building Council network to drive the implementation of resource efficiency actions to scale sustainable built environments for everyone, everywhere.”

WorldGBC’s Circularity Accelerator

Circularity Accelerator is a WorldGBC global programme to catalyse the adoption of circular economy and resource efficiency in the building and construction sector.

To tackle the climate and resource impact of the built environment and to support the ambitions of the UN’s Sustainable Development Goals and the Paris Agreement, WorldGBC’s Circularity Accelerator convenes the WorldGBC network of 70+ Green Building Councils and their 36,000 members to work towards WorldGBC’s circularity and resource efficiency goals:

– 2030 goal: The sustainable management and efficient use of natural resources within the built environment, achieving zero waste to landfill targets and working towards a built environment with net zero whole life resource depletion

– 2050 goal: A built environment with net zero whole life resource depletion, working towards the restoration of resources and natural systems within a thriving circular economy



Read more on the World Green Building Council’s article.

The featured image above is the Exchange, designed by Kengo Kuma and Associates. Kengo Kuma and Associates are known for projects examining the association between nature, technology, and human beings. Credit: Anne Czichos / Shutterstock.

Architect seeks pro-climate construction transformation


Architect seeks pro-climate construction transformation to be generalised throughout the Middle East and North African regions of heavy urbanisation.  

The above image is of Place Pasteur, Beirut


French-Lebanese architect seeks pro-climate construction transformation

Lina Ghotmeh has pegged her career on sustainable construction.

The French-Lebanese architect wants to see her industry transformed by drastically reducing the use of concrete — a major CO2 contributor — using more local materials and reusing existing buildings and materials.

“We need to change our value system,” the 42-year-old told AFP last month.

Lina Ghotmeh wants to reduce the use of concrete in building / © AFP

The aim is to reduce the carbon footprint of the construction industry and create buildings that can better resist the impacts of climate change.

But it’s not an easy battle.

The industry accounts for almost 40 percent of global greenhouse gas emissions, according to the United Nations.

Ghotmeh, who designed the Estonian National Museum and taught at Yale University, doesn’t advocate for fewer buildings — she knows that’s an unrealistic goal in a world with a growing population.

“That would be like saying ‘stop eating,'” she said.

– ‘Don’t demolish’ –

Instead, we should “keep what already exists, don’t demolish,” but refurbish and retrofit old buildings in a sustainable way where possible.

Building a new detached house consumes 40 times more resources than renovating an existing property, and for a new apartment complex that rises to 80 times more, according to the French Agency for Ecological Transition (Ademe).


Lina Ghotmeh’s ‘Stone Garden’ in Beirut uses traditional building techniques / © AFP/File

And where new constructions are needed, local materials and design should be used in a way that incorporates natural surroundings and saves energy.

Ghotmeh used more than 500,000 bricks made from local dirt for a new Hermes building in France, expected to open early next year.

The bricks also regulate the building’s temperature and reduce energy needs.

The building will produce as much energy as it consumes, by being made energy efficient and using geothermal power.

– ‘Circular thinking’ –

Architects must, early in the project process, “think in a circular way,” Ghotmeh said, choosing reusable organic or natural materials like wood, hemp, linen or stone.

This shouldn’t stymie the design process either, she insists.

“In Canada, we build wooden towers, in Japan too. It’s a material that is quite capable of being used for tall buildings,” added Ghotmeh, who will build a wooden tower in Paris in 2023.

Another key approach is to build lighter, using less material and fewer toxins.


Transforming the concrete jungle / © AFP

And then there’s concrete, the main material in so many modern buildings and perhaps the most challenging to move away from.

“We must drastically reduce the use of concrete”, she said, insisting it should only be used for essential purposes, such as foundations and building in earthquake-prone areas.

Some 14 billion cubic metres of concrete are used every year, according to the Global Cement and Concrete Association.

It emits more CO2 than the aviation industry, largely because of the intense heat required to make it.

Alternatives to concrete already exist, such as stone, or making cement — a component of concrete — from calcium carbonate. There are also pushes for low-carbon cement made from iron and steel industry waste.

– Beirut inspiration –

Building more sustainably often comes with a higher price tag — it costs more to double or triple glaze windows and properly insulate a house — but the long-term payoff is lower energy costs.

For Ghotmeh, it’s an imperative investment in our future.

It was her birthplace of Beirut that inspired her to become an architect, spurring a desire to rebuild the so-called “collapsed city” ravaged by war.


The wall of Ghotmeh’s ‘Stone Garden’ / © AFP/File

In 2020, she completed the “Stone Garden” apartment tower in the city, built with concrete covered with a combed coating, a technique often used by local craftsmen. She used concrete in the construction because of earthquake risks.

The building was strong enough to survive the port explosion in 2020 that destroyed a large part of the city.

And the city continues to inspire her today, even when it comes to climate sustainability.

“Since there is practically only an hour of electricity per day, all the buildings have solar panels now. There is a kind of energy independence which is beginning to take place, by force,” she said.

“Does it take a catastrophe like the one in Lebanon to make this transition?”




Living materials are the future of sustainable building

A Pennsylvania State University RESEARCH on living materials that are the future of sustainable building has elaborated on this aspect of the building materials and / or their combination as illustrated by the above image of Jose Duarte, professor of architecture, and doctoral student Elena Vazquez adjust panels on a prototype of a dynamic window shading system that Vazquez designed and built.  Credit to: Patrick Mansell. All rights reserved.  If this goes through, we could safely say that building sites will look a bit different in the future.